The applicant has already proposed a pass-through fishing rod (Japanese Utility Application No. 88259/93) where a fishing line extends through the hollow center of the fishing rod. The gist of the proposal is the formation of notched/protrusive inner-circumferential surface in the fishing rod material made from resin and reinforcing fibers. By such a structure, a fishing line can be held by the protrusive portions and lifted up from the inner-surface of the fishing rod so that the friction resistance which is generated by winding and unwinding of the fishing line can be mitigated.. If a spiral is stored within the fishing rod and forms protrusive portions as shown in the Japanese Patent Application No. 304836/89, for example, there is a problem that this spiral could come off the inner-surface of the fishing rod when the rod is bent because the protrusive portions and the inner-surface are separate things. In the prior application stated in the Japanese Utility Application No. 88259/93, however, the inner-surface of the fishing rod itself forms protrusives. Therefore, the protrusive portions should not come off when the fishing rod is bent.
As mentioned above, though the prior art has already had a basic effect that the protrusive portions hardly come off the inner-surface of the fishing rod, this structure does not offer sufficient strength for use in a long run as the fishing rod material itself forms protrusive portions. Therefore, some countermeasure has been needed to solve this problem.